2- propane synthesis procedure

Alkaline earth oxides (AEO = MgO, CaO, and SrO) doped with 5 mol% Nd203 have been synthesised either by evaporation of nitrate solutions and decomposition, or by sol-gel method. The samples have been characterised by chemical analysis, specific surface area measurement, XRD, CO2-TPD, and FTIR spectroscopy. Their catalytic properties in propane oxidative dehydrogenation have been studied. According to detailed XRD analyses, solid solution formation took place, leading to structural defects which were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the alkaline-earth ion size match with Nd3+. Relationships between catalyst synthesis conditions, lattice defects, basicity of the solids and catalytic performance are discussed. 

A mechanistically interesting synthetic procedure for the synthesis of vinylcyclo-propanes was reported in 1997 by Takeda [33] (Figure 3.34, Table 3.3). 

Cyclobutanone is an important synthetic starting material (e.g. see Expt 5.41) recently a simple synthesis from readily available materials has been reported.6 The synthesis (Expt 7.13) involves the formation of l,3-bis[bromo-magnesio]propane and its further reaction with carbon dioxide to form the complex (36), which precipitates from solution thus simplifying the purification procedure. Although the overall yield is low (13%), this is compensated for by the cheapness of the reagents and the simplicity of the procedure. 

Synthesis. 2-(Dimethylmaleimido)-7V-ethylaciylamide (DMIAAm) monomer was prepared according to the procedures mentioned in the literature [29],. S -Acctoxy (3-di-methylmaleimido)-propane thiol (ADP) (Scheme 1) as an adhesion promoter was synthesized according to the procedure mentioned in the literature [20],... 

Lignin Models. l-(4-Hydroxy-3-methoxyphenyl)-2-(2-methoxyphcnoxy)propan-1,3-diol (VII). The 4-benzyloxy-a-keto precursor to VII was prepared as previously described (16), Treatment of this compound (70 mg, 0.17 mmole) in THF(2 mL)/H2O(0.1 mL) with 10% Pd/C under H2 (balloon), with stirring, for 3 hours gave a colorless oil (49 mg, 91%) which was shown to be VII by comparison (TLC and NMR) with authentic material. A 70 30 erythroAhreo ratio was indicated by 13C-NMR. The XH and 13C-chemical shifts (CDCI3) have been previously published (17), Compound VII enriched with 13C at Ca was prepared from labeled acetovanillone, which was prepared from guaiacol and acetic acid-l-13C by a procedure analogous with that described previously (16), The 7-13C enriched compound was made by simply utilizing 13C-formaldehyde in the synthesis. 

With regard to the synthesis of the oligo-cyclo-propane natural product FR-900848 (1) multiple and consecutive cyclopropanation reactions using zinc carbenoids have been applied. Thus, in the total synthesis of 1 by Barrett et al. the Furu-kawa-procedure was used for the conversion of 52 into the biscyclopropane 53 (Scheme 11). [37] After bidirectional elongation of the molecule, another double cyclopropanation of diene 54 using Charette s catalyst gave tetracyclopro-pane 55 in 93 % yield as one stereoisomer only. Finally, the olefin 56 is cyclopropanated at -40 °C to yield the desired pentacyclopropane alcohol 57. Thus, all five cyclopropane rings of... 

A modification of this general procedure was used in the synthesis of (prop-2-enylidene)cyclo-propane (allylidenecyclopropane, 12).Allyl bromide was first alkylated in 81 -90% yield with l-lithio-l-(phenylsulfanyl)cyclopropane (10) in the presence of copper(I) iodide or cop-per(I) iodide-dimethyl sulfide. The adduct was then methylated with methyl fluorosulfonate or with dimethyl sulfate, and the sulfonium salt cleaved with powdered potassium hydroxide in dimethyl sulfoxide, to give the product in 50-70% overall yield for the second step. 

Enders has used these asymmetric Michael additions as the key steps in the enantioselective synthesis of various esters and alcohols (69-73) which are chiral volatile ant pheromones. In these syntheses, asymmetric Michael additions of the lithio salt of the SAMP hydrazone of propanal to methyl 2-but-enoate and methyl 2-pentenoate were used to establish the chiral centers. Subsequent hydrolysis and reduction of the aldehyde or carboxylic acid ester by conventional procedures afforded the pheromones. ... 

The zinc-based Simmons-Smith type procedures frequently require rather harsh conditions in order to provide acceptable cyclopropane yields. Also, the discrimination between allylic alcohols, homoallylic alcohols and olefins without a hydroxyl group is often not very pronounced. These drawbacks are avoided by a new method which substitutes samarium metal (or samarium amalgam) for zinc (Table 4)43. This cnahlcs only allylic alcohols to be cyclo-propanated under very mild conditions, even for highly crowded substrates. The hydroxy-directed diastereofacial selectivity is good to excellent for cyclic olefins. Due to this property, the method has been applied to the stereoselective synthesis of 1,25-dihydroxycholecalciferol44. 

The general procedure for the Ireland rearrangement is demonstrated by the stereocon-trolled synthesis of syn- and at f/-3,4-dimethyl-5-hexenoic acids 1 from ( )- or (Z)-crotyl propan oates91. 

The enantiomer of phenylalaninol methyl ether, (+ )-(/ )-2-amino-l -methoxy-3-phenyl-propane [(7 )-8] can be obtained by the same procedure from (/ )-phenylalanine, but a more inexpensive synthesis from commercially available synthetic (-)-(,S, S)-2-amino-l-phenyl-1,3-propanediol (Section 2.3.2. for this and related amino alcohols) via an intermediate dihydroox-azole has been developed. 

General procedure 2, copper metal-catalyzed synthesis of 1,2,3-triazoles [6, 23]. Phenylacetylene (2.04g, 20mmol) and 2,2-bis(azidomethyl)propane-l,3-diol (1.86g, lOmmol) were dissolved in 1 2 tert-butanol/water mixture (50mL). About 1 g of copper metal turnings was added, and the reaction mixture was stirred for 24 h, after which time TLC analysis indicated complete consumption of starting materials. Copper was removed, and the white product was filtered off, washed with water, and dried to yield 3.85 g (98%) of pure bis-triazole product. 

Ring expansion induced by FeCla has been used in a new synthesis of dl-muscone in 237> overall yield from dimethyl tetradecanedioate, which was converted into (6) by the procedure of Ruhimann (4, 537). In this case cyclo-propanation with methylene iodide and diethylzinc (4, 153) proved superior to the Simmons-Smith reagent. ... 

The compositional modulation technique has been applied to the Fischer-Tropsch synthesis (FTS) reaction [2-5], It was found that the cyclic feeding of CO/H2 had an influence on the selectivity of the FTS products. Among the conclusions was that for an iron catalyst the selectivity for methane increased under periodic operation compared to the steady state operation [5], In the study [5] it was found that the propane/propene ratio increased under periodic operation and the largest changes were with periods between one and ten minutes. Due to the limitations of the anal5dical technique utilized, they could not separate ethane and ethene so that the selectivity basis was for the C3 hydrocarbons. In this study the analytical procedure permitted analysis of products only to the Cg-compoimds. 

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